Sandblasting 101 for old cast iron and tools. BEST METHOD???????

[drivesitfar]

All: so i've heard most of the members talking about sandblasting old cast iron vises and tools say it's best to use glass bead. while a few others are saying sandblasting is ok or even better.

i've seen some TV shows where they shoot thin material with walnuts, hazelnuts and even sodium so looking for the members that might have the FACTS to share.

Anybody want to share with us which method is best for sandblasting old tools if you have the ability and don't want to use Electrolysis or some chemical method.

Please post your honest opinions or FACTS

thanks in advance

i'm hoping to buy a Skatblast cabinet when i move and get my own BIG shop and for now i'll be using this homemade sandblaster or paying to have it done if i don't use Electrolysis.

 

[Al Borland]

Depending on the cast iron(especially porosity), sand may leave a very rough, pitted surface.
Glass bead is less aggressive, some of the others are more of a "green" option.
As far as sodium blasting, I think you mean soda blasting/ It's slower, much less aggressive, and may/will need to be neutralized before paint or finishing(big P.I.T.A. on a porous casting).

 

[McBrownie]

Some car service centers use walnut shells for cast parts like intake manifolds, etc...

http://www.eastwood.com/blast-media-walnut-shells-50-lb.html

 

[crguy]

I use beads mostly, depending on the situation. Beads don't alter the surface as much as sand.
It takes a lot of air to run a blaster.

 

[countryroad82]

I'm in the glass beads camp. Pretty much use it for all my blasting needs. When I've done cast iron I've not noticed anything bad going on. I should have thrown my vise in the cabinet when I cleaned it up to show how it doesn't hurt anything other than rough the surface up.

 

[OccupantRJ]

Glass beading regularly at work (one cabinet) and home (two cabinets) for over 30 years. Blasted 4 hours yesterday, and 2 hours today. Blast everything from carburetor parts to cast iron with beads, never change air pressure, never needed to. Thick paint may need to be removed with paint remover to save cabinet time, but the beads will produce a nice surface finish. Items with heavier flaking rust are best done with more agressive abrasives. I keep aluminum oxide in one of my personal cabinets for this. I also paint mechanical items after blasting without using primer and have no problems getting paint to adhere. These are the facts you requested.

 

[drivesitfar]

ALL: any of you have any pictures to show of your set ups either at home or at work with brands and specs would be great. also before and after pictures of some projects would be AWESOME. especially if you can do a similar type project with two or three applications so we can all SEE which one works better in those situations.

i've done a little research on blast cabinets and at this point i think my purchase when i move and get my new shop i'll buy a SkatBlast made one. either in pieces and assemble it or have it ship assembled if my new home cost allows me to.

anybody have a favorite brand or system they made at home or in their shop they want to mention please do.

thanks

 

[OccupantRJ]

Get a end door model cabinet. The lift lids put grit in unsuspecting eyes when raised. A cyclone separator is the key to a good cabinet, other than the choice of suction or pressure fed gun. This is of course assuming a good air supply. Linking this to my media blasting thread.

 

[blazemaster83]

Howdy, I bought the Desmond Stephan 63s from you. The cabinet I use is a Pauli & Griffin 36x36. Not a huge cabinet but for me the size works great. Currently connected to a 60 gallon 5hp devilbiss compressor and it cannot keep up with the cabinet. The lines on the cabinet are 1/2" ID. I quickly found out that compressor won't cut it if I actually want to blast some stuff. I have tried glass beads, a mix of glass and alum ox, and just alum ox. I prefer alum ox for what I do.

I poured a small slab and am in the process of building a small shed to house a larger compressor. I bought two 250 gallon tanks to stack up and tie together. I picked up a used quincy 390 that I am rebuilding and a 10hp motor. I posted this in a similar thread on another forum.

Here is the slab, nothing fancy



Heres the cabinet, it has a seperator on the back.





Heres one of the tanks, the other is pretty much identical but white



Here is the mighty quincy 390 before teardown (about 650lbs.)



Here is my RPC, I upgraded to 15hp from 10hp, so I could run the 10hp motor.

 

[drivesitfar]

Blaze: happy to hear from you and sorry my laptop crashed several times so i no longer have your email and contact information. sent you a PM.

nice looking HUGE motor and tanks. i hope it works out for you. some of the guys were saying the old Quincys are not worth restoring, but it looks like you will prove them wrong. good luck

ALL: thanks for your posts and comments so far and if you can post pictures and more information i'm sure i (we) will be grateful.

 

[ZRX61]

I use mostly glass or plastic, sometimes soda (for carbs to brighten them after plastic).

You can also use chalk for electrical stuff, this is a before & after of some parts from a WWII German aircraft:

 

[Roberts210]

I know you wrote that you don't want to use electrolysis, but maybe you should reconsider. I have used electrolysis on everything from the wheel cylinders below to a 6-cylinder head, to the entire convertible top of my '53 Chevy, using a 6-amp voltage transformer that sits in a home-made electrolysis power unit I made for less than $10. (The convertible top I disassembled into 6 pieces and each large piece spent 4-5 days and nights in the tank.)

These '53 Chevy wheel cylinders sat on a parts car, a few inches above Missouri mud for over 30 years. They both looked like the one on the left before electrolysis. The one on the right shows what happens after a day in the elec. tank. It's cheap and easy.

 

[OccupantRJ]

Electrolysis seems like a good process, but a hell of a slow one. It would take me years for all the parts I work with.

 

[countryroad82]

If I can ever make it back to my shop I'll take some pics of my setup along with do some blast comparisons for you. Just give me a day or 2 lol, this newborn stuff is new to me!

 

[zkling]

The thing with abrasive blasting (of which sand used to be the most common abrasive) is not only was it designed to "clean" the part, but to also texture the surface at the same time. The degree of abrasive used depended on the end goal; which usually was a repaint.

With modern abrasives such as glass, walnut, corn, etc, the secondary finishing characteristics have been able to be altered.

The problem with abrasive blasting machined components is that it will frost the surface. Again depending on the pressure, angle, abrasive used to different degrees. It is a texture that is very distinguishable, irreversible and to me just looks hack. It takes away resolution of the surface, especially if features are present.

Where abrasive blasting has and pretty much will always shine is for paint prep work as it strips and preps* in one step. *To a certain degree.

 

[drivesitfar]

Roberts: i didn't say i wasn't going to use Electrolysis and just the opposite. i'll probably use that more than sandblasting.

the reason why i started this thread wasn't all for just me. some of us seem to think sandblasting 50 to 200 year old cast iron is no different than using glass bead or other materials in your blast cabinets.

ALL: thanks for the good posts so far and any of you that have or can take and post pictures please do because we all would love to see before and after and or comparison side by side pictures.

thanks

 

[txvwnut]

Research blasting media you'll see they actually list what types of metal they perform well on and what the finish surface will be like after blasting. My setup is a HF blast cabinet with a TP Tools gun upgrade kit in it and I use garnet for my media. The garnet pretty much leaves steel and iron a light gray to white in color after blasting. If I was to do any blasting outside of the cabinet I would most likely use sand as it's cheaper than the garnet, or I would use soda but soda's not good at removing rust.
There's also different grits to the media and that plays a large part in what you are wanting to blast and how it turns out.

 

[astroracer]

For this kind of blasting, cast iron, tools, junk stuff, I use Black Diamond from Tractor Supply. It's cheap, cuts quickly and leaves a very nice finish.
Here are a couple of threads where I have been using it.
http://www.garagejournal.com/forum/showthread.php?t=317419

http://www.garagejournal.com/forum/showthread.php?t=315579

 

[bulletpruf]

I have an 80 gallon 2 stage Quincy; able to easily keep up.

Harbor Freight blast cabinet - the big one. Has paid for itself over and over again.

I usually use aluminum oxide in the cabinet. I have glass beads and walnut shells, but haven't tried either yet.

I have hoppers that I use for blasting outside. Those get filled with blasting sand. If I'm doing a lot of blasting, I'll do it on a tarp and when I'm done, I reclaim the sand for a few more rounds. Black Beauty is nice, too. IIRC, it comes in 3 different grades. The coarsest one is pretty aggressive.

If I'm going to paint something, I like to blast it - quick, easy, and leaves a lot of tooth for the paint to adhere to. If it's going to stay bare metal, no blasting for me. Surface just doesn't look right.

 

[drivesitfar]

ALL: if any of you can take a few pictures of your sandblasting set ups and post a some here that would be great. also if you have pros and cons to add that would be great. one of the biggest concerns or maybe complaints is that the smaller compressors can't handle all the output of sandblasting. how do YOU get around that without owning a commercial 3 phase system?

BP: you wrote down almost exactly what i've been thinking was the best methods to own and use a sandblaster that would PARE nicely with Electrolysis.
any pictures of your set up?

 

[OccupantRJ]

A picture of my large cabinet before restoration can be seen in post #8 of this thread.

http://www.garagejournal.com/forum/showthread.php?t=61583

Here is my smaller glass bead cabinet

http://www.garagejournal.com/forum/showthread.php?t=124933

 

[srvctec]

Why do you need a cabinet at all? Can't you just do this outside?

Well yeah, except when it's raining or snowing or 10 below zero or any combination of the above. Then you need some sort of hood and other protection depending on pressure and media used.

 

[bulletpruf]

ALL: if any of you can take a few pictures of your sandblasting set ups and post a some here that would be great. also if you have pros and cons to add that would be great. one of the biggest concerns or maybe complaints is that the smaller compressors can't handle all the output of sandblasting. how do YOU get around that without owning a commercial 3 phase system?

BP: you wrote down almost exactly what i've been thinking was the best methods to own and use a sandblaster that would PARE nicely with Electrolysis.
any pictures of your set up?

Drives -

From a few years ago when I lived in Georgia. Shortly after the Quincy arrived.



Harbor Freight blast cabinet. An 80 gallon compressor should be plenty big enough to keep up with a sandblaster. Certainly does the job for me.

If you look to the right of the press on the floor, you can barely make out a pair of black plastic hoppers. These are very simple units - just a hopper with a hose and sandblasting gun. These are from Sears.

Scott

 

[semi42]

just a warning guys..., it is illegal in the UK to use most common forms of sand for abrasive blasting, as the fine dust particles which are created when the sand is projected at high speed, can cause silicosis – a potentially fatal lung disease.
personally i think the best results come from vapour or wet blasting, a much cleaner finished end product

 

[countryroad82]

Ok was able to do a quickie comparison with my cabinet. Here is a run of the mill railroad spike I had laying around. I make knives out of them but anyway it's all I could find handy. I thought I had a cast intake but I guess I've either sold it or gave it away lol.


Here it is after 3 minutes in the cabinet using run of TSCs glass beads.



Just for fun since someone said something about the finish of blasting looking sub par, I hit it with a DA with some leftover 320 on it. Since the metal isn't smooth it didn't really get everything but I feel it gives one an idea of what you can do to bring the metal back out. If I were to polish the metal I would have knocked the edges down and smoothed it up then started with 180 and slowly bumped up my grits until I finished with 1,000.









Here is my TP Tools 970. It was well worth the money and is one of those tools I wish I bought earlier.







I need to change my stupid lens protector again but I rarely look through it anyway. That little space between the glass and the protector is the best line of sight I feel. Excuse the mess, got to remember my shop is a working shop lol. I keep the cabinet covered with a sheet and magnets across it to keep overspray off the glass. It's worked for me since it bought the thing. Anyway hope this helps any and at all. If you've got any more questions just give me a yell I'll be watching this thread for awhile.



Sent from my iPhone using Tapatalk

 

[countryroad82]

ALL: if any of you can take a few pictures of your sandblasting set ups and post a some here that would be great. also if you have pros and cons to add that would be great. one of the biggest concerns or maybe complaints is that the smaller compressors can't handle all the output of sandblasting. how do YOU get around that without owning a commercial 3 phase system?

I just checked this thread to see if anything more had come up and came across this post. I'll take a pic of my compressor setup but it's just an Eaton 2 stage with an 80 gallon tank. I've never had any air loss problems when running my setup for extended periods of time, it keeps up fine for me. It does have a continuous run switch that I can turn on for times when I am blasting but I don't believe I've ever found the sense to do it. But it is just a run of the mill 220 volt system. I don't have 3 phase at my shop at all.

Back when I had a 60 gallon single stage compressor, I would have to stop and let the compressor catch up occasionally as I could run it out of air while blasting. I'm a firm believer that is one of the reasons I killed that compressor 3 times before I replaced it....... running DAs and paint guns constantly didn't have anything to do with it either......

About the only problem I've ever had with my setup wasn't my fault. Well it was to an extent but not totally. I had a buddy call me and ask to use my cabinet to clean up an intake. I told him before he brought it over to get ALL grease and oil off of it before bringing it over. I was busy when he came and he just went straight to the cabinet and started blasting. A little while later he was complaining it was clogging up too easy....... Yeah that intake was nowhere near clean. So he learned an expensive and hard earned lesson because he got to buy me fresh media, replaced all my intake lines, plus he got to wrestle my cabinet out of the shop, pressure wash it, scrub it absolutely clean, and put it all back. I love it when people don't listen to me.

There are way too many pros to the setup as long as you keep good media in it. I wish I had bought mine sooner to say the least it is one of those tools that has proven itself to be so invaluable even if sometimes it will sit for months on end without using it. Back when I was doing more restoration work I couldn't live without it!!

 

[Mark in Indiana]

Drives,

I used 10mil glass bead media in the past, with great results. This stuff was gentle enough to be used for compressor rebuilds by an authorized Quincy service shop. IMO: regardless of the media, don't over blast.

I no longer have access to that set-up, so it's just my wire wheels and e-tank for cleaning.

 

[don long]

Drivesitfar

As you may know I do a lot of blasting in my blast cabinet
I use 80 grit garnet on all the cast iron pieces and don't notice any metal gouging the pieces are much to thick to worry about distortion

I built my own cabinet. I turned this

Into this

It's a 10 foot container that I welded a man door and an 8' roll up door into

I purchased a portable blasting unit for my box

and bought a self contained helmet with an air supply system.

To supply my air I found an old air compressor, diesel powered and it delivers a constant 175 cfm more than enough to supply my needs

 

[countryroad82]

You win Don!!!!

 

[countryroad82]

I might add that I have often fantasized about building such a setup. But before I do such I need to build a dedicated paint booth more. I also would like a lift after building a booth. Dang its depressing thinking of the **** I should do. Before the lift I NEED to get a car or two out of the shop and make them mobile. Word of advice kids, don't start 2 frame off restorations, run a business, have a family, and try to keep in touch with friends!! UGH!!!!

 

[ratdoggy]

Don...That has to be the most bad *** setup I've ever seen

 

[drivesitfar]

RD: you couldn't have said that better about Don's cool "SMALL" blast cabinet.

DON: thanks for stopping in and sharing your COOL set up. I might have more questions later, but for now do you have any more before and after pictures to share of what you are cleaning up inside there. also some more of the details on how you use it or even video if you are able would be awesome. I've seen pictures of your AWESOME Garage that changes to a MAN CAVE in minutes and I need to get in your thread and look at it closer knowing you can almost blast a small car in that cabinet you built.

CR: thanks for the before and after pictures and the great posts. i'll read them more thoroughly later as I start to sandblast and i'm sure they help others.

BP: mentioned on his Record vise repair thread that he owns 3 small plastic sandblast units that he keeps small amounts of different types of material in them so he has them at the ready to use on many small projects. I hope he posts a few pictures and some examples of his projects he's done or is doing too.

ALL: I have a wood crate on a pallet I can move outside or use in the shop for paint spraying now. it's 5 feet tall and about 4 feet wide and deep with a door on it that locks if I need it to. I might use it for sandblasting with my homemade set up I posted in the first couple posts. is there a HUGE or any negative from shooting in a big wood cabinet as long as your material isn't hitting it right out of the guns?

 

[ratdoggy]

Drivesitfar....You could just line the back of the cabinet with some sheet steel.
Replace as necessary. But I'll bet it would last a long time If it warps some wouldn't be a real problem..

 

[ratdoggy]

My set up...(only picture I could find)
I have the top load skat blast and their reclaimer[URL=http://s1073.photobucket.com/user/ratdoggy/media/P5200051.jpg.html] [/URL]

 

[don long]

Thanks guys.

drivesitfar
This is what went into the blasting box yesterday. I didn't snap an after shot. I just went right after the parts, sanding off the casting marks and rough casting finishes and using bondo to fill in the pits

This is how the piece started out

 

[bulletpruf]

Ok, here's my setup for blasting outside. I have the HF blast cabinet, but occasionally I have something too big. Anyway, I put a tarp down so I can reclaim the media, and that's a Sears plastic hopper and gun. I have three of them, each one loaded with different media depending on the job. I think they go for about $50 new (hopper and gun).

 

[drivesitfar]

RD: thanks for the tip on the metal liner for my crate and temporary paint or blast booth i have. your set up looks awesome for smaller items. can you see pretty well through the glass or plastic and how often do you need to clean or change it for a new one?

DON: what can i say but WOW that blast cabinet you built is awesome and the stuff you find to restore are very COOL. thanks for sharing and take and post more pictures as you can if you have time.

BP: thanks for posting and mentioning your hand sand blast units that are at the ready with different media for quick jobs.

ALL: i know this might be sort of a boring subject, but for those especially the young guys that didn't get SHOP class in school this might be the only way they can learn and see what sandblasting is all about.

SAFETY TIPS such as masks and full face shields are great and something some guys and gals might have not thought about.

speaking of safety is there anything you can do to get HURT or INJURE yourself that anybody has or wants to mention?

cheers and thanks guys (and gals if any want to post theirs)

 

[OccupantRJ]

Drivesitfar....You could just line the back of the cabinet with some sheet steel.
Replace as necessary. But I'll bet it would last a long time If it warps some wouldn't be a real problem..

Rubber pond liner would be a better material to line a blast cabinet or room as grit just bounces off it.

 

[OccupantRJ]

A safety tip. Sand rushing through rubber hose can generate potent static electricity. I was blasting an old car hood on sawhorses with my commercial rig when I was in my 20's and got my crotch too close to a corner of the hood. A 2 inch lightning bolt hit me right in the pecker! I remember that one 30 years later!

 

[OccupantRJ]

There is much info on blasting to be found in my abrasive blasting resource thread here.

http://www.garagejournal.com/forum/showthread.php?t=237844